Drafting-compasses.



No. 868,735. PATENTED OCT. 22, 1907.

J. D. WARD.

DRAETING GOMPASSES.

APPLICATION rn-nn 0111.29, 1907.

rut NORRIS PETERS co., WASHINGTON, o. c,

JOHN D. WARD, OF TULSA, INDIAN TERRITORY.

DRAFTING-COMPASSES.

Specification of Letters Patent.

Patented Oct. 22, 1907.

Application filed January 29, 1907. Serial No. 354,683.

To all 'uihom it may comm-n:

Be it known that I, John D. WARD, a citizen of the United States, residing at Tulsa, in the Creek Nation, Indian 'lerritory, have invented certain new and useful Improvements in DruHing-Compasses, of which the follmving is a specification.

This invention has for its object an improved construction of drafting compass, which may be quickly adjusted to the required radius and securely held in adjusted position for describing the desired circle, and the invention consists in certain constructions and arrangements of the parts hereinafter described and particularly pointed out in the appended claims.

For a full understanding of the invention and the merits thereof and also to acquire a knowledge of the details of construction of the means 'for eiiecting the result, reference is to he had to the following description and ac companying drawings. in which:

Figure .l is a perspective view of my improved drafting compass; Fig. 2 is a side elevation thereof, parts be ing broken away; and, Fig. 3 is a side elevation of a modification.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

Referring to the drawing, the numeral 1 designates the post of my improved drafting implement, said post be ing provided with a lower tapered or pointed end 2 designed to he used as the pivot, and also formed with the usual rounded head The post 1 is provided with slots 4 one above the other, and supporting bars 5 and (3 extend through said slots and are mounted to slide therethrough, the proportion oi the slots with respect to said bars being such that a slight relative rocking movement is permitted between the bars and post, so that the latter may be held at a slight inclination, while the device is in operation. Such inclined position, is illustrated in Fig. 2. The two bars 5 and 6 are preferably permanently connected together at one end by a stop 7, to limit the sliding movement of the post on the bars and prevent the post from becoming detached.

8 designates the leg of the implement, the same being arranged to hold either a pen or pencil as desired, and in one form or embodiment of the invention, this leg is rigidly secured to the other ends of the supporting bars 5 and 6.

9 designates a set screw which is mounted in the post 1 and is designed to impinge against one of the supporting bars, preferably the upper bar so as to hold the post on the bars at the proper adjustment. One oi the supporting bars is provided with lineal graduations, as in dicated in the drawing, and in the practical operation of the device, the post 1 is slid along the bars to the desired point, according to the length of radius of the circle it is intended to describe. The post is then secured to the upper bar 5 and the device manipulated in the custom ary manner.

As a modification of the device, I may, as indicated in Fig. 3 secure the post 1 in a permanent relation to the bars 5 and 6 at the middle thereof, by means of the set screw 9 and instead of moving the post relative to the bars, so mount the leg 8 upon the bars that said leg may be moved along to obtain the desired adjustment within certain limits.

From the foregoing description in connection with the accompanying drawing, it will be seen that I have provided a very simple and eflicient compass for draftsmans use, which embodies instead of the pivot legs that are usually employed, a post and a leg that have no direct connection, but that are mounted upon supporting bars in such a manner that one may be slid towards or away from the other and quickly secured in place to secure the desired adjustment, and in which a circle of a desired radius may be quickly described by adjusting the leg or post along the supporting bars.

By mounting the post 1 on the bars 5 and 6, so that it may tilt or cant thereon, it is obvious that the device may be very quickly adjusted and that the arrangement will tend to hold the post at an adjusted position along the bars, owing to the binding action when inclined, even if the set screw 9 were to be omitted. Furthermore, this susceptibility to a tilting or canting position enables the device to be used with the post so inclined as to facilitate the describing of arcs and circles, as the entire device will thus partake of the characteristics of the ordinary pivoted leg compasses.

Having thus described the invention, what is claimed as new:

A drafting compass comprising a pair of spaced supporting bars, a leg mounted upon the said bars at one end and holding such ends in spaced relation to each other, a stop connecting the other ends of the bars; the leg being adapted to hold a pen or pencil, and a post provided with upper and lower openings through which the said bars extend, the openings in the post being of greater length than the height of the bars and providing a free open space between the upper and lower walls of the openings and the upper and lower edges of the bars, thereby permitting a canting or tilting movement or the post on the bars, as and for the purpose set forth.

In testimony whereof I arlix my signature in presence of two witnesses.

JOHN D. WARD. [L. s.] Witnesses Gnonon BENER, C. M. THOMPSON. 

